As a traditional industrial sector, the achievements of the domestic paper industry in environmental protection in the past 10 years cannot be questioned. However, it must be admitted that the paper industry is still the number one member of the "COD emission club" and bears enormous pressure to reduce emissions. Guo Yongxin, deputy director of China Light Industry Information Center, said not long ago that the output value of the pulp and paper industry accounts for 0.88% of the country's total industrial output value, but COD emissions account for 35%, which determines that the industry is difficult to maintain the status quo for a long time. According to reports, the expected emission reduction target proposed by the paper industry is a reduction of 10.4% in COD emissions, with an average annual reduction of 2.2%. While the output maintains growth, it will drop from 1.06 million tons in 2010 to 950,000 tons in 2015.
"In the 12th Five-Year Plan, the paper industry mainly achieves the goal of reducing pollutants through structural emission reduction and in-depth treatment." Wu Yueying, director and senior engineer of the Total Control Office of the Water Environment Planning Department of the Chinese Academy of Environmental Planning, told reporters that they are the main reasons for pollutant emissions. The industry has conducted an accounting of the total emission and emission intensity, and it is estimated that the emission reductions of industrial COD and ammonia nitrogen are about 1.2 million tons and 100,000 tons.
Wu Yueying analyzed that in terms of structural emission reduction, during the "Twelfth Five-Year Plan" period, for papermaking enterprises, Suzhou dangerous goods packaging manufacturers require the elimination of alkali-free recycling (sulfate method) pulping production lines, with a single production capacity of less than 34,000 tons. Non-wood pulp chemical pulp production lines, waste paper production lines with a single production capacity of less than 10,000 tons, chemical wood pulp production lines with an annual production capacity of less than 50,000 tons that do not meet the pollutant emission standards, and some ammonium-based pulping. According to estimates, it is estimated that papermaking will be eliminated. The production capacity is 8 million tons. In terms of in-depth treatment, it is mainly through accelerating the transformation of water-saving technology, improving the recycling rate of industrial water, and strengthening the construction of pollution control facilities.
She specifically mentioned the "Water Pollutant Discharge Standard for Pulp and Paper Industry" implemented on August 1, 2008. "According to the discharge standard, the emission reduction of papermaking wastewater will make a great contribution to the total control of industrial sources." Wu Yueying said that when the standard was introduced, we also had doubts, how many companies can meet the standard with such strictness? In the subsequent investigation of Changshu heavy-duty dangerous goods containers, we found that many large enterprises can meet the standards, and the treatment costs are not unbearable.
The continuous improvement of environmental protection standards is putting pressure on the self-adjustment of the paper industry. After the first stage of standard implementation, all pulp and paper enterprises are required to implement the (COD) emission limit of 100mg/L or less. Wu Yueying said that it must be admitted that there are still many papermaking enterprises that do not meet this requirement, and this is also the space for further emission reduction in the papermaking industry.
"First of all, it is necessary to promote clean production. If nothing is done, it is difficult to achieve the standard by only relying on terminal biochemical treatment." Wu Yueying said that whether it is an alkali method or an acid method, the pulping process must recycle the waste liquid. It can be said that if there is no recycling process, it can basically be directly determined that the enterprise cannot meet the standard. Resource recovery and utilization measures such as black liquor extraction, alkali recovery, and white water recovery can all reduce the load of terminal treatment.
While proposing the reduction tasks for the industrial sector, the relevant research groups of the Environmental Planning Institute also considered relevant feasible technologies and processes. Taking the paper industry as an example, firstly, the source treatment process should be determined according to the types of raw materials and products, the source and nature of wastewater (chemical pulp production system adopts measures such as energy and chemical recovery, recycling process water; mechanical pulp and chemical pulp production system should be Adopt measures such as cleanup and diversion, circulating process water, fiber recovery, etc.; papermaking production system should adopt measures such as circulating process water and white water recovery); , the secondary treatment process including the anaerobic unit and the necessary advanced treatment can reach the standard in the end treatment link.
"Companies must increase investment, but it has not increased to an unacceptable level. The increase in environmental protection costs may indeed eliminate some small enterprises with low pollution control levels to a certain extent." Wu Yueying said. According to people in the paper industry, the investment in the production capacity of 10,000 tons of paper industry has reached 100 million to 150 million yuan, which is basically the same as the investment in heavy industries such as steel and petrochemicals.
As for the new control indicator ammonia nitrogen, Wu Yueying said that the problem in the paper industry is not big. "We cooperated with the Paper Association and found that for the paper industry, the sources of ammonia in wastewater include ammonium pulping wastewater, excess nutrients added by wastewater biochemical treatment plants, raw starch in corrugated wastewater, and plant raw materials. ammonia, etc."
Among them, the ammonium-method pulping waste liquid and the excessive addition of nutrient salts are the main sources of excessive ammonia nitrogen discharge in the papermaking industry. For small-scale ammonium chemical pulping enterprises, the concentration of ammonia nitrogen in wastewater is 2 to 4 times that of large and medium-sized enterprises, which leads to an increase in the treatment cost, so that some small-scale enterprises cannot afford it. Therefore, in the "Twelfth Five-Year Plan" emission reduction measures, a number of ammonium pulping enterprises are considered to be eliminated. For enterprises that add excessive nutrient salts to increase the ammonia nitrogen concentration in papermaking wastewater, which leads to increased operating costs, the increase in operating costs is entirely caused by poor management of the enterprise, and ammonia nitrogen emissions should be reduced by improving the operation and management requirements of enterprise wastewater treatment facilities.
As a major emitter, the paper industry will follow the example of the power industry to list the total amount or even increase the project approval right? Wu Yueying said that as a heavy polluting industry, the paper industry may implement regional and industry total control in the future. For example, if there is no water pollution index for the paper industry that has been reduced in a certain place, new papermaking projects cannot be launched. The policy effect will be very direct.